GIS BASED ANALYSIS OF FLUVIAL LANDFORM CHANGES OF A LARGE BRAIDED RIVER

Abstract

Land use planning in alluvial river valleys and the choice of locations for bridges and hydraulic structures require predictions of future river plan form changes. The usual mathematical models for river morphology are based on the conservation of mass and momentum of small volumes of water and sediment , where as predictions of river bank migration commonly span long periods of time. There is a considerable gap between the scales of the phenomena and the limitations of this approach. The change in stream bed profile with respect to time and space .follow no certain rule. Modeling the stream bed profile has always posed a challenge to the engineers and research workers in the field of river engineering. In general the cross section profiles of a river are irregular in shape and size making it quite difficult to represent mathematically. Braided rivers form important topic of study because of the high rates of sediment transport, deposition and erosion combined with frequent channel shifting and rapid bank erosion. In the above context , an attempt has been made in this dissertation to evaluate the trends of fluvial land form changes of the river Brahmaputra to certain approximation due to hydrographic data constraint. Special emphasis has been laid for the study of Majuli island, the largest river island in the world on the basis of the available data.....